Re: pg_isready docs doesn't specify what exactly it is checking

On Fri, 7 Jan 2022 at 03:29, Euler Taveira <euler(at)eulerto(dot)com> wrote:

> On Tue, Jan 4, 2022, at 3:11 PM, PG Doc comments form wrote:
>
> We could include a sentence explaining that a port probe is not a
> sufficient
> condition to successfully connect to a Postgres server because the state
> machine has more than 2 states. PQping [1] already states "reports the
> status
> of the server" and describe each state it provides. Feel free to suggest an
> improvement to documentation.
>

A diagram of the state machine would be very useful.

There is no known issues with pg_isready and that report isn't clear. He
> says
> "database and/or user wasn't available". What's the exact error message? If
> there is a reproducible test case, share it here.
>

PostgreSQL docker image can run initialization scripts at container start to
create database, users and maybe load some data. So when pg_isready
reports success, the DB can still be in an inconsistent state for an app to
start
using it.
--
Anatoli Babenia